Sarah Palin, the former Alaska governor and 2008 vice-presidential nominee who became a Tea Party sensation and a favorite of grass-roots conservatives, will endorse Donald J. Trump in Iowa on Tuesday, officials with his campaign confirmed. The endorsement provides Mr. Trump with a potentially significant boost just 13 days before the state’s caucuses.

“I’m proud to endorse Donald J. Trump for president,” Ms. Palin said in a statement provided by his campaign.

Her support is the highest-profile backing for a Republican contender so far.

“I am greatly honored to receive Sarah’s endorsement,” Mr. Trump said in a statement trumpeting Mrs. Palin’s decision. “She is a friend, and a high-quality person whom I have great respect for. I am proud to have her support.”

Mrs. Palin, who is to appear alongside Mr. Trump at a rally on the Iowa State University campus in Ames late Tuesday afternoon, could amplify the news media-circus aspects of Mr. Trump’s candidacy: Like him, she is a reality-TV star accustomed to playing to the cameras and often accused of emphasizing flash over substance.

But Mrs. Palin, who despite her waning visibility within the Republican Party retains a sizable following, provides Mr. Trump with valuable new currency at a moment when he is being attacked over his conservative bona fides by Senator Ted Cruz of Texas, with whom Mr. Trump is neck-and-neck in the Iowa polls.

Wow. I dunno, that’s pretty YUGE.

Or not. I think this will help Palin raise her profile more than it will help Trump. The Donald is doing it just to grab headlines, but Palin’s importance, relevance and reach among conservatives has been significantly eroded and diminished.

Where is “Conservatism” on a map? How many people live there? Personally, I live in The United States and it’s being burned to the goddam ground by movement marxists. The democrat party is going to nominate a fucking communist to lead them. The republican party is not. There is nothing else to know. Anyone who thinks there is more to know is a retard who should not be allowed to vote. Grow the fuck up. Cruz ’16.